With all due respect, Mr. Carter (and I do respect your work very much), most knifemaking books do call the "left" side (the side towards your body when sheathed on the right hip or held in the right hand) the presentation/obverse side. I don't know why exactly.
For that matter, I don't know if it's proper to have a maker's mark aligned so the bottom of it lines up with the guard/bolster etc, so the person holding it can read it (which seems to be most common by far) or oriented the other way, so if you hold the knife normally and show it to someone else, they can read it. Mr. Burke has a very good point, orienting it so the guard etc. is the "underline" does make it easy to read and looks good... but so could the plunge line. A matter of taste, I suppose.
The term "presentation side" makes me think of holding the knife and showing it to someone else so they can see the marks, etc.... that's why I get confused. Probably just me thinking too much
I'm only guessing, but I still think it's up to the individual maker or client to decide. The knives I make most often are 5" blades or less, and I try to get the usable bevel/edge as close to the guard/handle as I can. So marking on the ricasso isn't an option, because there's very little ricasso to begin with.
When I get my etcher and stencils squared away, I'll be putting my mark on the presentation/obverse side, near the spine, on the bevel itself, close to the plunge. An etch of the steel type and/or other pertinent info will go on the reverse side, also near the spine/plunge. For no other reason than it looks good there, and makers I admire seem to do it that way.